Irostenka

Not sure what you want to achieve here. But as a first step I'd alway check what's available on turbosquid etc. It's usuallly easier to buy something close and tweak it rather than start from scratch (unless you have  larger budget). ie: https://www.turbosquid.com/3d-models/rigged-and-animated-horse-v2-clydesdale-953668